These apparatuses are mainly used for transporting light articles, especially workpieces. The articles rest on a conveyor chain either directly or with the aid of transport pallets, which conveyor chain is moved along a guideway. The guideway serves for guiding the conveyor chain on a conveying track defined by the guideway.
In known apparatuses of the aforementioned type, the conveyor chain which is formed from a plurality of coupled chain parts slides along tile stationary (immovable) guideway. This is the reason why such apparatuses are only used for transporting relatively light articles. Nevertheless, even the transport of light articles has drawbacks because the conveyor chain slides along the guideway. These drawbacks are particularly high running noises, relatively strong driving forces and a quite substantial wear and tear.
Known apparatuses of this type are also used in conjunction with accumulation tracks. In this case, some articles come to a standstill on the conveying track while the conveyor chain is still driven. The conveyor chain slides along underneath the articles which are to be transported, which also leads to the aforementioned drawbacks.
Furthermore, the known apparatuses of this type are suitable only for transporting certain articles, especially transport pallets carrying these articles. If, for example, it is intended to use transport pallets which must be retained or guided on the conveyor chain, the guideways have to be provided with guides for the respective transport pallets. In this respect, the known apparatuses suffer a lack of flexibility.
Finally, another drawback of the known apparatuses, especially when they are used in assembly lines, is that the access to the transported articles, on which assembly work has to be carried out, is restricted. The articles can not be accessed from underneath because in known apparatuses of this type the conveyor chain is disposed underneath the articles.